Accès ouvert
2004
article
OpenAlex
J.Z. Bai, Y. Ban, J. G. Bian, J. F. Chang et autres
Using 58 million $J/\ensuremath{\psi}$ events taken with the BES II detector at the Beijing Electron Positron Collider, the decay $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{f}_{2}(1270){f}_{2}(1270)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ is observed, and the branching fraction $Br(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{f}_{2}{f}_{2})=(9.5\ifmmode\pm\else\textpm\fi{}0.7\ifmmode\pm\else\textpm\fi{}1.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ is measured for the first time, where the quoted errors are statistical and systematic, respectively. …
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J. Z. Bai, Y. Ban, J. G. Bian, Xingzhen Cai et autres
Cross sections and form factors for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\pi}}^{0}$, $\ensuremath{\rho}\ensuremath{\eta}$, and $\ensuremath{\rho}{\ensuremath{\eta}}^{\ensuremath{'}}$ at center of mass energies of 3.650, 3.686, and 3.773 GeV are measured using data samples collected with the BESII detector at the BEPC. Also, the branching fractions of $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\pi}}^{0}$, $\ensuremath{\rho}\ensuremath{\eta}$, and …
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J. Z. Bai, Y. Ban, J. G. Bian, X. Cai et autres
Results are presented on $\ensuremath{\psi}(2S)$ and $J/\ensuremath{\psi}$ hadronic decays to ${K}_{S}^{0}{\mathrm{pK}}^{\ensuremath{-}}\mathrm{n\ifmmode \bar{}\else \={}\fi{}}$ and ${K}_{S}^{0}\overline{p}{K}^{+}n$ final states from data samples of 14 million $\ensuremath{\psi}(2S)$ and 58 million $J/\ensuremath{\psi}$ events accumulated at the BES II detector. No $\ensuremath{\Theta}(1540)$ signal, the pentaquark candidate, is …
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J. Z. Bai, Y. Ban, J. G. Bian, X. Cai et autres
Using $\ensuremath{\gamma}\ensuremath{\gamma}J/\ensuremath{\psi},J/\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\psi}}{e}^{+}{e}^{\ensuremath{-}}$ and ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ events from a sample of $14.0\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ decays collected with the BESII detector, the branching fractions for $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}J/\ensuremath{\psi},$ $\ensuremath{\eta}J/\ensuremath{\psi},$ and $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c1},\ensuremath{\gamma}{\ensuremath{\chi}}_{c2}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}J/\ensuremath{\psi}$ are measured to be $B[\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}J/\ensuremath{\psi}]=(1.43\ifmmode\pm\else\textpm\fi{}0.14\ifmmode\pm\else\textpm\fi{}0.12)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3},$ $B[\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\eta}J/\ensuremath{\psi}]=(2.98\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.23)%,$ $B[\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c1}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}J/\ensuremath{\psi}]=(2.81\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.23)%,$ and $B[\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c2}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}J/\ensuremath{\psi}]=(1.62\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.12)%.$
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J. Z. Bai, Y. Ban, J. G. Bian, X. Cai et autres
Using $J/\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\psi}}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decays from a sample of approximately $4\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ events collected with the BESI detector, the branching fractions of $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\eta}J/\ensuremath{\psi},$ ${\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}J/\ensuremath{\psi},$ and anything $J/\ensuremath{\psi}$ normalized to that of $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ are measured. The results are $B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\eta}J/\ensuremath{\psi})/B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=0.098\ifmmode\pm\else\textpm\fi{}0.005\ifmmode\pm\else\textpm\fi{}0.010,$ $B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}J/\ensuremath{\psi})/B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=0.570\ifmmode\pm\else\textpm\fi{}0.009\ifmmode\pm\else\textpm\fi{}0.026,$ and $B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\mathrm{anything}J/\ensuremath{\psi})/B(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=1.867\ifmmode\pm\else\textpm\fi{}0.026\ifmmode\pm\else\textpm\fi{}0.055.$
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J.Z. Bai, Y. Ban, J. G. Bian, Xuanming Cai et autres
The CP violating processes J / ψ → K 0 S K 0 S and ψ (2 S )→ K 0 S K 0 S are searched for using samples of 58 million J / ψ and 14 million ψ (2 S …
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J.Z. Bai, Y. Ban, J. G. Bian, J. F. Chang et autres
Inclusive momentum spectra and multiplicity distributions of charged particles measured with the BESII detector at center of mass energies of 2.2, 2.6, 3.0, 3.2, 4.6 and 4.8 GeV are presented. Values of the second binomial moment ${R}_{2}$ obtained from the multiplicity distributions …
cn, us
(code pays fourni par la source)
Accès ouvert
2004
article
OpenAlex
J. Z. Bai, Y. Ban, J. G. Bian, Xuanming Cai et autres
The branching ratio of $J/\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\psi}}{K}_{S}^{0}{K}_{L}^{0}$ is measured with improved precision to be $\mathcal{B}(J/\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\psi}}{K}_{S}^{0}{K}_{L}^{0})=(1.82\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.13)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ using $J/\ensuremath{\psi}$ data collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider. This result is used to test the perturbative QCD prediction between $\ensuremath{\psi}(2S)$ and $J/\ensuremath{\psi}$ decays …
cn, us
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